Amazon needs new tablets to protect its online-media business.

Steve Kovach, Business Insider

The Kindle tablet family started life as simple e-book readers. But they now do it all: surf the Web; store books, music, and videos; and play games. The last category is the most interesting part of Amazon's strategy to watch. Just as Amazon has gotten into book publishing, it's started making its own games, to assure that Kindle users will have a big library of titles to play.

Apple may announce a smaller iPad to make sure it's got a device for everyone.

Associated Press

Late Apple cofounder Steve Jobs dismissed the idea of a smaller tablet. But the recent Apple-Samsung patent trial revealed that Apple was seriously considering a device with a 7-inch screen. Now, spurred by competition from Amazon and Google, Apple is widely expected to come out with its own smaller tablet this fall.

For Apple, it's a continuation of a longstanding strategy to offer a more complete lineup of mobile devices that rivals can't match. For kids and teens, it has the iPod Touch; for most users, the iPhone; and for older adults who like a bigger screen, the iPad. An iPad Mini fills in some gaps in that lineup—for example, women who want a device that fits easily in a pocketbook.

Google needs people to use its Web services.

Owen Thomas, Business Insider

Google got a jump on Apple in the small-tablet market, with the Google-branded Nexus 7 in July. Next, it may offer models with built-in 3G wireless. But Google isn't making hardware for hardware's sake: These devices showcase its Google+ social network, Gmail, and Google Play, its online store for apps, music, books, and video.

Microsoft is still figuring out its strategy, but it's all about developers.

AP

Microsoft is building its own Surface tablet, due out in October, while its traditional PC partners make competing Windows RT and Windows 8 tablets. It also wants to compete in digital media, phasing out its Zune brand in favor of Xbox Music and partnering with Barnes & Noble for a Nook e-book reader app. But what's Microsoft's goal? Bottom line: It has to keep software developers in the Windows orbit.